Software Engineer — Language Design

About PostHog

We <u>equip every developer to build successful products</u>.

We started with open-source product analytics, <u>launched out of Y Combinator's W20 cohort</u>.

We've since shipped <u>more than a dozen products</u>, including <u>a built-in data warehouse</u>, <u>a customer data platform</u>, and <u>PostHog AI</u>, an AI-powered analyst that answers product questions, helps users find useful session recordings, and writes custom SQL queries.

Next on the roadmap are messaging, customer analytics, ai task creation and coding based on customer data, logs and support analytics.

Our<u> values</u> are not a poster on the wall full of aspiration. They’ve come from how we really work, day in day out.

PostHog is <u>Open Source,</u> product led, and a <u>default alive</u> company that is well funded.

What you'll be doing

If you ever dreamed of writing your own coding language and having it be used by hundreds of thousands of people, the this job is for you.

Because PostHog has created two languages that power almost all our products and we're not done yet.

PostHog SQL (aka HogQL) is our SQL dialect that wraps ClickHouse SQL, and provides a safe and flexible way to query data in our systems. Any data that's queried and returned to our app goes through this layer.

Hog is our programming language used to transform data in our realtime pipelines. Hog is SQL-compatible, and runs in a bytecode VM that can be embedded into Python, TypeScript and Rust programs.

You will be building and expanding our language capabilities.

Some examples of what you might be working on are: adding support for objects into the Hog language, adding the create table statement to our data warehouse, or improving the select <SparkLine /> query tag for product analytics.

You’ll have a large impact on the company since every engineer in the company interacts with this layer, as well as most external users.
You’ll also need to keep up with the latest developments of the downstream query targets and document languages thoroughly.

You’ll fit right in if:

• You’re a builder. You bring strong skills in building software at a product company and solid language design skills.
  For the language design we’re talking about actual practical implementation versus theoretical research, preferably in a work environment.

• You have good knowledge of what’s out there. You are keeping up with the latest developments of the downstream query targets (Postgres, ClickHouse, DuckDB, Athena, etc.)

• You have experience building compilers and/or interpreters

• You bring experience with writing complex ANTLR grammar.

• You bring programming and SQL skills. Python and C++ are a must, so is SQL. Experience with Rust is welcome.

• You love getting things done. Engineers at PostHog have an incredible amount of autonomy to decide what to work on, so you’ll need to be proactive and just git it done.

• You’re ready to do the best work of your career. We have incredible distribution, a big financial cushion and an amazing team. There’s probably no better place to see how far you can go.

If this sounds like you, we should talk.

We are committed to ensuring a fair and accessible interview process. If you need any accommodations or adjustments, please let us know

What’s in it for you?

Now that we've told you what you'll be building with us, let's talk about what we'll be building for you.