Database Engineer - Fully Remote

Mercor; Berlin; Remote; EUR 90,000 - 130,000; Full time

Job summary

Mercor is seeking a senior database engineer to craft real-world tasks for AI agents handling database internals. The role focuses on designing challenging, self-contained challenges, checks, and performance criteria across storage engines, query execution, and transactions.

You will collaborate with technical reviewers and shape pilot tasks for top candidates. Applicants should have 5+ years in database-engine internals or a database-systems PhD, with strong coding in C/C++, Java, Python, or Go

Qualifications

• At least five years of hands-on database-engine internals experience, or a database-systems PhD.
• Deep experience with storage engines, query execution, optimization, transactions, replication, or related low-latency systems.
• Strong implementation skills and clear explanations of correctness and performance tradeoffs.

Responsibilities

• Design one challenging, self-contained database engineering task.
• Build checks for correctness, failure handling, concurrency, retries, and regressions where relevant.
• Evaluate performance measures such as latency, throughput, and memory use.
• Write clear grading criteria for engineering judgment.
• Work with technical reviewers to refine and validate the task.

Skills

Database internals

Storage engines

Query execution

Transactions

Low-latency systems

Education

Database systems PhD

Tools

C

C++

Java

Python

Go

Job description

Applications close Tuesday, October 13, 2026 at 12:00 p.m. Pacific. We are selecting the first three applicants who qualify for the initial pilot.

About the work

Build real-world tasks that test how well AI agents handle database engineering. Depending on your specialty, your task may cover database-engine implementation, production diagnosis, or application migration.

Each task should include a clear problem statement, a reproducible repository or environment, a working reference solution, tests, and grading criteria that distinguish a robust engineering solution from one that only appears correct.

What you'll do

• Design one challenging, self-contained database engineering task.

• Build checks for correctness, failure handling, concurrency, retries, and regressions where relevant.

• Evaluate performance measures such as latency, throughput, and memory use.

• Write clear grading criteria for engineering judgment.

• Work with technical reviewers to refine and validate the task.

Who we’re looking for

• At least five years of hands‑on database‑engine internals experience, or a database‑systems PhD.

• Deep experience with storage engines, query execution, optimization, transactions, replication, or related low‑latency systems.

• Strong implementation skills and clear explanations of correctness and performance tradeoffs.

DBA, SQL analytics, ETL, or application‑only database experience does not qualify on its own. You do not need to specialize in every task area.

Application process

Complete a self‑paced technical assessment with written responses and a coding exercise. You control when to advance between sections. (~35 min)

Use a laptop or desktop with a camera, microphone, and entire‑screen sharing. Have your own editor and terminal ready, along with Python 3.8+ and a compiler for C, C++, Rust, Go, or Java. The assessment includes a starter kit and public tests. Complete the assessment independently, without outside AI assistance.

We will select the first three qualifying applicants. If the pilot fills, completed assessments may be considered for future work if the project expands.

Paid task after selection

Selected experts will complete one task, with approximately 25 hours of work, followed by technical review and feedback.

Task deadline: Friday, October 30, 2026.