#067: You Don't Need To Know Every Data Tool & Skill

career May 29, 2024

You do not need to know every data tool and skill, and you will not find anyone who does. The better goal is fluency: knowing enough of the landscape to follow a conversation, pick up an unfamiliar tool, and be effective on a team. It is the same goal you would set if you were learning French or German. You would not try to memorize the dictionary, you would aim to hold a conversation in the country. Three things get you there in data: a project you actually find fun, your own end to end playground stack, and a job you treat as paid practice. That mindset has guided how I have learned for the past decade.

Key takeaways

  • The goal is to be fluent in data engineering, not to memorize every tool and language. Fluency means you can navigate the conversation even when you do not know everything.
  • Roadmaps and tool lists are useful for getting the lay of the land. They become a problem when you treat them as a checklist you have to finish before you are allowed to feel competent.
  • Pick a subject you actually care about for your first projects. I used sports and music data because they were interesting enough to keep me going.
  • Ten rows in a table is enough to learn the foundations. The volume does not matter, the practice with tables, keys and relationships does.
  • A playground stack costs far less than people assume. Open source options are free, cloud providers have trials, and nothing runs much when it is only you using it.
  • Most of us join a company in the middle of a system that was already built, which is exactly why we feel inadequate. Building your own small version gives you back the part you missed.
  • There are still seasons when you need to go deep on one tool. That is different from trying to go deep on all of them at once.

Fluency, not a complete vocabulary

When we learn technical things, most of us assume we are supposed to know everything. I see it constantly in comments: people asking for the roadmap, the full list of tools, the complete set of skills.

Some of that is reasonable. You do want the lay of the land so you know what exists and roughly where it fits.

The trap is treating the list as a finish line. Compare it to learning a spoken language. If I set out to learn German, memorizing the dictionary would be a strange goal. What I actually want is to go to the country and navigate a conversation.

Even when you do not know every word, you know enough to be effective. I have spoken English my whole life and there are still plenty of words and phrases I do not know.

What fluency looks like in data

Fluency in data engineering means you can hold the conversation. You understand how the pieces connect, you can reason about a tool you have never touched, and you can ship something that works.

That is a different target than "I need to know everything about SQL, everything about Python, and how to use every tool." The second one just overwhelms you, and it does not get you the outcome you actually want.

If you do want the map, I put one together in What Tools Should You Know as a Data Engineer?. Read it as a map of the landscape, not as a checklist.

Three things that built my fluency

Looking back at my own path, three habits did most of the work. I still use all three.

1. Build a project you actually find fun

The best thing you can do is come up with a project that is genuinely fun for you. Same idea as the language analogy: you want to talk about things you find interesting, not read sentences out of a textbook.

I have always been into sports, so one of the first things I did was figure out how to gather data on sports. Before I even got to gathering, I created a database and manually inserted data on leagues and teams in the city.

I like music too, so I built tables for artists, their record labels, where they were from and who they were affiliated with. Just IDs, names and relationships.

Each table had about ten records, and that was fine. Volume is not the point. You are learning the foundations of database objects, and ten rows teaches that as well as ten million.

2. Stand up your own playground stack

Once the basics clicked, I started asking how to pull data in from outside, and then how to automate it. You keep layering until you have something more robust.

That is exactly what a company does. They start from scratch and slowly build. The problem is that most of us get dropped into the middle of something already built, next to people who have been there for years, and we feel completely inadequate because we missed the whole building phase.

Building your own playground stack gives that phase back to you. It is one of the better career assets you can own.

People talk themselves out of it on cost. There are plenty of open source options you can run without a license, cloud providers have free trials, and if you are not running things constantly it is not expensive.

The questions your playground stack should answer

Start simple and add components. The questions you are answering are the same ones any company has to answer:

  • How do you get data in
  • Where are you storing it, and how does it get there
  • How are you transforming it
  • How are you visualizing it
  • How are you automating all of it

Work through those end to end on your own stack and you have practiced the actual job.

3. Take the perspective back to work

Once you have practiced on fun projects and built a playground, bring that perspective into your job. Try things. Recommend things. Apply what you learned.

Now you are getting real experience, and you are getting paid to keep learning.

A lot of this is just how you choose to look at the job. Work will be a pain plenty of the time. It is also an opportunity to keep learning on someone else's dime and do genuinely cool things.

I knew at some point I wanted to start a business. I did not know what it would be, but I figured data and technology would be the way, because it fit my personality. I am not the outward, sales focused type, I like being behind the scenes.

Learning on the job was how I prepared for a moment that did not arrive until years later. Having that goal in the background put everything else in perspective.

Seasons when you do need to go deep

None of this means you never specialize. There will be seasons where you need to go deep on one specific thing.

When I was learning SQL, I went down into query engines, execution plans and indexes. That was the right call at the time.

Depth in one place transfers. Once you get a real feel for how one database or one orchestrator works, you can apply most of that understanding to the next one.

It shows up in interviews too. You can say you have never used a particular tool, then explain what you understand about the concept and how you would approach learning it. With enough understanding and the right mentality, that answer usually lands.

Nobody knows it all

This is the part worth hanging onto. There is no one out there who knows every tool and every skill, no matter how confident or how good they are at their specific thing.

So do not sell yourself short because your list has gaps in it. Everyone's list has gaps.

Keep learning, aim at fluency instead of coverage, and the stress of the whole thing drops considerably.

Key terms

Fluency in data

Knowing enough of the data landscape to navigate a conversation, learn an unfamiliar tool quickly and be effective on a team, without knowing every tool.

Playground stack

A small end to end data stack you build and own yourself, used for practice rather than production, usually on open source tools or free cloud tiers.

Fun project

A practice project built on a subject you genuinely care about, chosen so that curiosity carries you through the parts that are tedious.

Seasons of depth

Deliberate periods where you go deep on one tool or concept, as opposed to trying to go deep on everything at the same time.

Roadmap

A published list of the tools and skills in a field, useful for orientation and harmful when it becomes a checklist you feel you must finish.

Common questions

Do I need to learn every data tool to get a data engineering job?

No. Job descriptions list far more than any one role uses day to day. What matters is that you can explain how the pieces of a stack fit together and show you can learn a new tool when a team needs it.

What should I build for my first data project?

Pick a subject you already care about so the curiosity carries you. Create a small database, insert a handful of records by hand, and build out the tables and relationships. Ten rows per table is enough to learn the foundations.

How much does a personal data stack cost to run?

Less than most people expect. Many of the components have free open source versions, the cloud providers offer trials, and usage based pricing stays low when you are the only user and nothing runs on a schedule.

Is it still worth going deep on one tool?

Yes, in seasons. Going deep on one database or one orchestrator teaches you concepts that transfer to the next one. The problem is trying to go deep on everything at once, which is what leaves people stuck.

Why do I feel so far behind my teammates?

Usually because you joined in the middle of a system someone else spent years building. You missed the construction, so the finished thing looks like knowledge you are missing. Building your own small version gives you that phase back.

What do I say in an interview about a tool I have never used?

Say that directly, then explain the concept behind it and how you would go about learning it. Showing that you understand the category and have a method for picking things up is usually more convincing than a shallow claim of experience.

Related reading

Final takeaway

Every small data team I work with runs on a handful of tools, not on a complete roadmap. The engineers who do well there are the fluent ones who can reason about a stack and learn the next piece when it shows up.

 

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