Python Crash Course Notebook for Data Engineering

Hey everyone! Sometime back, I put together a crash course on Python specifically tailored for Data Engineers. I hope you find it useful! I have been a data engineer for 5+ years and went through various blogs, courses to make sure I cover the essentials along with my own experience.

Feedback and suggestions are always welcome!

📔 Full Notebook: Google Colab

🎥 Walkthrough Video (1 hour): YouTube \- Already has almost 20k views & 99%+ positive ratings

💡 Topics Covered:

1. Python Basics \- Syntax, variables, loops, and conditionals.

2. Working with Collections \- Lists, dictionaries, tuples, and sets.

3. File Handling \- Reading/writing CSV, JSON, Excel, and Parquet files.

4. Data Processing \- Cleaning, aggregating, and analyzing data with pandas and NumPy.

5. Numerical Computing \- Advanced operations with NumPy for efficient computation.

6. Date and Time Manipulations\- Parsing, formatting, and managing date time data.

7. APIs and External Data Connections \- Fetching data securely and integrating APIs into pipelines.

8. Object-Oriented Programming (OOP) \- Designing modular and reusable code.

9. Building ETL Pipelines \- End-to-end workflows for extracting, transforming, and loading data.

10. Data Quality and Testing \- Using `unittest`, `great_expectations`, and `flake8` to ensure clean and robust code.

11. Creating and Deploying Python Packages \- Structuring, building, and distributing Python packages for reusability.

Note: I have not considered PySpark in this notebook, I think PySpark in itself deserves a separate notebook!

https://redd.it/1qr93s8
@r_devops

Devops Project Ideas For Resume

Hey everyone! I’m a fresher currently preparing for my campus placements in about six months. I want to build a strong DevOps portfolio—could anyone suggest some solid, resume-worthy projects? I'm looking for things that really stand out to recruiters. Thanks in advance!

https://redd.it/1qr5t6q
@r_devops

How do you track and manage expirations at scale? (certs, API keys, licenses, etc.)

Hey folks,

I’m curious how other teams handle time-bound assets in real life. Things like:

* TLS certificates
* API keys and credentials
* Licenses and subnoscriptions
* Domains
* Contracts or compliance documents

In theory this stuff is simple. In practice, I’ve seen outages, broken pipelines, access loss, and last minute fire drills because something expired and nobody noticed in time.

I’ve worked in a few DevOps and SRE teams now, and I keep seeing the same patterns:

* spreadsheets that slowly rot
* shared calendars nobody owns
* reminder emails that get ignored
* “Oh yeah, X was supposed to renew that”
* "There is too much tools for that and people don't communicate properly on the new time-bound assets or the new places where they are used"

So I wanted to ask the community:

**How are you handling this today?**

Some specific questions I’m really interested in:

* Where do you store expiration info? Code, CMDB, wiki, spreadsheet, somewhere else?
* Do you track ownership or is it mostly implicit?
* How far in advance do you alert, if at all?
* Are expirations tied into incident response or ticketing?
* What’s broken for you today that you’ve just learned to live with?

I’m especially curious how this scales once you’re dealing with:

* multiple teams
* multiple cloud providers
* audits and compliance requirements
* people rotating in and out

If you’ve had a failure caused by an expiration, I’d love to hear what happened and what you changed afterward, if anything.

Context: I’m a DevOps engineer myself. After getting burned by this problem a few too many times, I ended up building a small tool focused purely on expiration lifecycle management. I won’t pitch it here unless people ask. The goal of this post is genuinely to learn how others are solving this today.

Looking forward to the war stories and lessons learned.

https://redd.it/1qrdfm8
@r_devops

Resources for Debugging Best Practices

Do you guys have any books, papers, videos or other resources to develop a more disciplined or systematic approach to debugging, either in the infrastructure / system space or just general software development? I feel like I spend a huge amount of time debugging, and while learning through experience is great, I’d love to know if there were any books that you found useful.

Edit: when I say debugging I guess I should broaden it to also include like troubleshooting — debug suggest mostly code or terraform files or something, but maybe there’s more basic principles to think about

https://redd.it/1qreise
@r_devops

How do you catch cron jobs that "succeed" but produce wrong results?

I've been dealing with a frustrating problem: my cron jobs return exit code 0, but the actual results are wrong.

I'm seeing cases where noscripts complete successfully but produce incorrect or incomplete results:

* Backup noscript completes successfully but creates empty backup files
* Data processing job finishes but only processes 10% of records
* Report generator runs without errors but outputs incomplete data
* Database sync completes but the counts don't match
* File transfer succeeds but the destination file is corrupted

The logs show "success" - exit code 0, no exceptions - but the actual results are wrong. The errors might be buried in logs, but I'm not checking logs proactively every day.

I've Tried:

1. Adding validation checks in noscripts - Works, but you have to modify every noscript, and changing thresholds requires code changes. Also, what if the file exists but is from yesterday? What if you need to check multiple conditions?
2. Webhook alerts - requires writing connectors for every noscript, and you still need to parse/validate the data somewhere
3. Error monitoring tools (Sentry, Datadog, etc.) - they catch exceptions, not wrong results. If your noscript doesn't throw an exception, they won't catch it
4. Manual spot checks - not scalable, and you'll miss things

The validation-in-noscript approach works for simple cases, but it's not flexible. You end up mixing monitoring logic with business logic. Plus, you can't easily:

* Change thresholds without deploying code
* Check complex conditions (size + format)
* Centralize monitoring rules across multiple noscripts
* Handle edge cases like "file exists but is corrupted" or "backup is from yesterday"

I built a simple monitoring tool that watches job results instead of just execution status. You send it the actual results (file size, record count, status, etc.) via a simple API call, and it alerts if something's off. No need to dig through logs, and you can adjust thresholds without deploying code.

How do you handle simillar cases in your environment?

https://redd.it/1qrjfqc
@r_devops

AWS vs Azure - learning curve.

So...sorry, dnt mean to hate on Azure, but why is it so hard to grasp..

Here's my example, breaking into cloud architecture, and have been trying to create serverless workflows. Mind you I already have a solid understanding, as I am currently in the IT field.

Azure functions gave me endless problems....and I never got it working. The function never got triggered. No help provided by Azure in the form of tips etc. Certain function plans are not allowed on the free tier, just so much of hoops to jump through. Sifting through logs is daunting, as apparently you have to setup queries to see logs.


AWS on the other hand, within 2 hours, I was able to get my app up and running. So much help just with AWS basic tips and suggested help articles.

Am I the only one which feels this way about Azure..



https://redd.it/1qrl93k
@r_devops

Asked for honest feedback last month, got it, spent January actually fixing things

a few weeks ago I posted here about OpsCompanion. You told me where it sucked and what was cool. Appreciate everyone who took the time to try it.

I was an sre at Cloudflare.. I know that behind every issue is a real person just trying to do their job. Keeping things secure, helping devs out, or dealing with stuff getting thrown over the fence....

And now everyone is vibe coding with zero context or concern about prod. Honestly I am a little worried about where this is all headed.

I see what we are all dealing with and I want to help. Would love to hear what would actually make your days easier...really. not just another AI SRE thing.

Check it out: https://opscompanion.ai/

If it still sucks, let me know and I will fix it.

https://redd.it/1qroxnu
@r_devops

Will this AWS security project add value to my resume?

Hi everyone,

I’d love your input on whether the following project would meaningfully enhance my resume, especially for DevOps/Cloud/SRE roles:

Automated Security Remediation System | AWS

Engineered event-driven serverless architecture that auto-remediates high-severity security violations (exposed SSH ports, public S3 buckets) within 5 seconds of detection, reducing MTTR by 99%
Integrated Security Hub, GuardDuty, and Config findings with EventBridge and Lambda to orchestrate remediation workflows and SNS notifications
Implemented IAM least-privilege policies and CloudFormation IaC for repeatable deployment across AWS accounts
Reduced potential attack surface exposure time from avg 4 hours to <10 seconds

Do you think this project demonstrates strong impact and would stand out to recruiters/hiring managers? Any suggestions on how I could frame it better for maximum resume value?

Thanks in advance!

https://redd.it/1qrw38y
@r_devops

How do you manage database access?

I've worked at a few different companies. Each place had a different approach for sharing database credentials for on-call staff for troubleshooting/support.

Each team had a set of read-only credentials, but credentials were openly shared (usually on a public password manager) and not rotated often. Most of them required VPNs though.

I'm building a tool for managed, credential-less database access (will not promote here).

I'm curious to know what are the other best practices that teams follow?

https://redd.it/1qsjswf
@r_devops

From QA to DevOps - What’s your advice?

Hi everyone,

I’m currently working as a Software Quality Engineer with a background in test automation, and I’m planning to transition into a DevOps role within the next 1-2 years in EU job market.

I already have hands-on experience with:

Docker
Linux
Some Kubernetes basics
Some basics with CICD Pipelines (Gitlab, GitHub Actions)
Grafana & Prometheus
Networking

My background is mainly in automation, noscripting, and system reliability from a QA perspective. I’m now trying to identify the most effective next steps to become a solid DevOps candidate in Europe.

For those who’ve made a similar move (QA/SDET → DevOps), especially in the EU:

Which skills or tools should I prioritize next (I am currently getting deeper into Kubernetes)?
What kind of practical projects actually help in EU hiring processes?
Are certifications (e.g. AWS, CKA, etc.) valued, or is experience king?
How can I best position my QA background as an advantage?

https://redd.it/1qsi7kl
@r_devops

Honestly, would you recommend the DevOps path?

This isn't one of those "DevOps or other coolnoscript.txt?" question per se. I'm wondering if you'd genuinely recommend the path to becoming a DevOps. Are you happy where you are? Are the hours making you questioning your life choices etc. I'm looking to hearing genuine personal opinions.

I have a networking background and I currently work as a network engineer. I have several Cisco, AWS and Azure certifications and I have been doing this for a while. I fell in love with networking instantly and I still love it to this day. However it's a lot of the same and I have to travel/be away from my family more than I'd like. I have diagnosed ADHD which I am medicated for and it's been a blessing in my life. However, it's no secret that we get extra bored of repetitive tasks if there's nothing new and exciting.

Here I feel like the DevOps career is something that could be right up my alley, the amount of knowledge you need to have to just get started, the constantly changing environment, the never ending learning and the fact that there always seems to be something to do. Please correct me if I'm wrong.

I am now legible for a "scholarship" of sorts to get a 2 year DevOps education for free and I wonder if you'd take that chance if it was you? I was super excited until I realised that I have barely done any coding and sure there's courses in coding covered in this education but there are also many other things. But since I have experience in other things covered I could focus more on the coding aspect. Do you think two years will be enough experience to get into a junior DevOps role without being a burden to said company?

Thank you for your time.

/M

https://redd.it/1qssoqt
@r_devops

Astrological CPU Scheduler with eBPF

Someone built a Linux CPU scheduler that makes scheduling decisions based on planetary positions and zodiac signs with eBPF and sched_ext...and it works! Obviously not something to run into production, but still a fun idea to play around with.

"Because if the universe can influence our lives, why not our CPU scheduling too?"


https://github.com/zampierilucas/scx\_horoscope

https://redd.it/1qrzpbr
@r_devops

Getting pigeon-holed in my career - Need advice

A little background of myself, I have been working for the same company, in the same team since I graduated a few years ago. I had gotten an internship with them while I was studying CS and was lucky enough to get a FT role as soon as I graduated with the same team. Now the issue is this is a small team that purely does infrastructure automation for a big bank. I work with other infrastructure engineering teams and help automate many of their flows and create them into ansible pipelines. My company doesn’t even have terraform, we use Azure built in Azure Bicep to do IaC for cloud and use Ansible to do IaC for onPrem, I have minimal exposure to cloud, have only done a few automation and integrations with them.

With this job I have become an Ansible expert, and I am now knowledgeable on all the basics of Infrastructure Engineering especially onPrem however I don’t see a path upwards in my career and wanted advice on how to break out of this pigeon hole as a Ansible Automation expert to more conventional Cloud/DevOps Engineering.

What are maybe some certs I can pursue? What are some other ways to take my skill and expand on it? Just feeling stuck…

https://redd.it/1qspv6s
@r_devops

Underground office has a sulfuric smell

I work in a windowless office one floor underground, about 3 m (10 ft) from a large server room. There’s also a large cabinet nearby with a tunnel underneath it carrying thick cables.

Last week the room smelled sulfurous—like fart gas or stovetop gas. Not the extremely putrid “rotten egg” H₂S smell, but a persistent sulfur/fart odor.

A building inspector initially dismissed it, but a safety professional later tested the room with a 4-gas detector (O₂, CO, NO₂, SO₂, H₂S). No detectable H₂S was found, even though the odor is still present after testing.

Building management claims renovations upstairs may have disturbed plumbing (e.g., drilling into a sewer pipe), and advised heavy ventilation. It didn't smell today at the morning, but it's almost lunch and I smelt it again. Now my head hurts.

My concern is whether it’s safe to continue working there. If this were H₂S, smell would not be a reliable warning at dangerous concentrations, so I’m trying to assess risk without being paranoid.

I've used a career tag cause this seems to be more metawork than actual work.

https://redd.it/1qsvcqe
@r_devops

Who owns GitHub/vcs policies and compliance at your company?

Like specific things in GitHub settings such as which branches should be protected (when you have multiple orgs and those orgs all disagree on which branches should be protected), etc.

https://redd.it/1qsp2jo
@r_devops

Update to my “Al was implemented as a trial in my company, and it's scary.”

I’ve made a [post\](https://www.reddit.com/r/devops/s/rgLaBXNe7W) here a couple of months ago where my company was experimenting with implementing AI, this post is an update to how it went and what happened.

The company stopped hiring any “infra personnel” and started utilizing AI to do things like create and configure some AWS machines and VPCs by just talking with the agent (using the CLI) with specific IAM policies just in case.

I thought this was just a problem with the company I am in but everyone I know has almost the exact same thing. I am not working anymore, I either use AI or when I start to use my brain, everyone around me answers with AI. I am not an angel, I am a junior that can’t learn properly because no one wants to, everyone wants AI and less human error.

The only thing it failed at was deep architecture like database migration and specific clustering, but everything else it simply just does it and when it doesn’t, we only have to do maybe a single thing to fix it.

I am leaving the DevOps as a field and getting into security (was really interested in it before) but I genuinely feel like I was trolled and did nothing, and maybe even soon security would be replaced with AI.

This post may be stupid to seniors, but as a junior and people starting, this is reality. We don’t learn, we don’t grow, we are the ones getting replaced and I see no field being currently resistant to that. I will just get into moltbook and doom scroll.

Thank you for everyone who helped me pave my devops path, it is really one of the best fields I’ve ever went in and honored to have been here even if just for a short while, hopefully where I live is the problem and not the entire planet.

https://redd.it/1qsy1ln
@r_devops

European infrastructure engineers - What's happening inside your companies regarding your dependency on US hyperscalers?

Everybody follows the news and sees what's going on.

In the Netherlands, this has sparked a debate on our dependence on US tech specifically AWS, Azure, and GCP for businesses and the government. Management at my working place (medium sized SaaS business) has instructed the operations team to start planning an exit strategy.

We will probably stay with AWS for the time being but will slowly move everything towards OSS components as long as it's a feasible option. This shift was already initiated last year by moving towards Kubernetes, but we still use a dozen AWS services. It's going to take some time to move to a more portable architecture.

I'm wondering: what's going on in your company or team? Do you think this trend will last?

https://redd.it/1qsyjdw
@r_devops

Almost twice (2x) the salary but high workload. Should I accept the new offer?

I have around 4-5 years of experience, and I'm in my late 20s, not married. Recently, I got a job offer from a startup, and I’m just thinking whether I should accept it. So let me brief.

The new offer’s take-home salary is almost twice the current job’s take-home salary. 80% increase. It’s a big jump as I see. For my experience, I’m pretty sure this is above the market range in my country. It’s difficult to find this kind of a job. Downsides are high workload and high risk.

So let me compare the current one and the new one.

Current job:

2 days per office job, with EPF,ETF and OPD, insurance coverage.
I’m a permanent employee, and have 3 months of notice period. So job security is high.
Current compay is large and spread across multiple countries with 1500+ employees.
Tech Stack is good. (Azure, ArgoCD, AKS, GitOps, LGTM stack, etc)
Culture is bit toxic and not supportive at all. I’m actually looking for a good job for a while.
Major releases happen 2 times per month.

New Job:

Fully Remote, USD salary, but no OPD/Insurance coverage.
Notice period is pretty low. When probation it’s 8 days and after probation it’s 4 weeks. So job security is pretty low as well.
It’s a startup, and have Sri Lankan Team, with employees in other countries as well. And it’s seems to be growing okay with funds.
Tech stack is OK/Good. (AWS, ECS, GitHub Actions, Cloudwatch, etc. )
Culture I’m not so sure. Seems it’s better than the current job.
Releases happen every week.

Both have similar kind of weekend works, once in around 2 months.

What I know is salary increase is high (80%), and the workload is high as well. As I heard few days per week I may have to work 12+ hours per day, may be even more, since this is a startup.

Current job’s workload is also sometimes getting higher. I believe the new one will be pretty high. And the new job security is pretty low as well with smaller notice.

For me it’s high risk, high income, high stress/ workload job.

Should I accept the new offer?? What’ your opinion. I like to hear from experienced people in the industry.

https://redd.it/1qt0aca
@r_devops

Linux packages - v2026.02.01 - Versions, files and directories

In operating systems with shared dependencies, we often don't know which program or version a particular file was in. This is a recurring problem in my daily work. That's why I created a public domain index with all the packages from the Arch Linux, Artix Linux, Black Arch Linux, and CachyOS Linux repositories.

It is in the public domain and is updated monthly.

https://archive.org/details/packages\_202602

https://redd.it/1qsyygh
@r_devops

My team should be renamed to talkOps

Some days I spend more time talking about reliability than actually improving it.

Standups, syncs, postmortems, pre-mortems, planning, re-planning, alignment calls... and by the time I get a quiet hour, I'm already drained.

get that communication matters, but at some point the work needs focus.

How do you protect deep work time without looking "unavailable"?

https://redd.it/1qvzhiv
@r_devops

Audits keep pulling senior engineers into work only they can explain

Growing tired of these audit cycles. We plan ahead and just when we think we’re ready senior engineers get dragged into explaining configs, workflows and edge cases that technically exist but aren’t documented in the most formal way.


It’s not wrong but it’s disruptive and hard to schedule around delivery. We want audits to be predictable not ifs buts and maybes.


How do we relieve the eng team of this work?

https://redd.it/1qvtb82
@r_devops