Senior Software Engineer — Data Services

Location: Remote, preferably within Europe-friendly time zonesContract: Long-term contractor agreement via DeelBase Salary: €4,000–€8,000 per month, depending on experience and location About A5 LabsA5 Labs(AceGuardian and QuintAce) are building a foundation model for strategic decision-making.We are proving it first in the world’s most demanding strategic games, then scaling it to competitive domains beyond poker. AceGuardian is our B2B AI platform, while QuintAce is our consumer AI coaching product.Our Data Services team is the data backbone behind the platform—building the pipelines, scoring infrastructure, and analytics that power our AI models and products. We are a remote-first team of approximately 120+ people, working globally across AI, data, gaming, and product. About the RoleWe are hiring a Senior Software Engineer to join our Data Services team.You will build and operate low-latency streaming systems and high-throughput analytical data services exposed through APIs. This is a hands-on, high-ownership role for someone who can take an ambiguous need from design through delivery and reliable production operation. ResponsibilitiesBuild and run scalable streaming and backend data systems with clear latency, throughput, and reliability targets.Own Apache Flink pipelines in production, including stateful processing, checkpointing, recovery, backpressure diagnosis, and safe savepoint-compatible upgrades.Design, build, tune, and operate ClickHouse at scale: data models, MergeTree engine choices, ordering and primary keys, partitioning, materialized views, ingestion, and query performance.Lead large-scale reprocessing and backfills end to end, with idempotency, replay, reconciliation, production safety, and verified correctness.Build and operate Kafka-based data flows, including partitioning/key design, consumer groups, replay, ordering, and failure handling.Work across teams on versioned data contracts and schema evolution using JSON Schema, Avro, or Protobuf.Build services and stream-processing workloads in production Python.Maintain strong engineering operations across Kubernetes, AWS, CI/CD, observability, load testing, on-call, and incident response.Write clear design docs, ADRs, and RFCs; communicate risks and dependencies early; and collaborate effectively across distributed teams.Use AI agents in your daily engineering workflow to accelerate execution while maintaining strong review and ownership standards. Required SkillsStrong production experience with both Apache Flink and ClickHouse at scale. These are non-negotiable requirements.Deep knowledge of stateful stream processing, including keyed state, deduplication, delivery semantics, state recovery, and backpressure.Strong production Python experience in services and/or stream processing.Experience operating Kafka at scale.Experience with an operational data store under real production read load, such as MongoDB or a comparable system, including indexing, query optimization, and latency diagnosis.Proven ownership of production migrations, backfills, replay, reconciliation, or parity verification.Strong system-design judgment and a practical, measured approach to safe delivery through staged rollouts, flags, and cutovers.Excellent written and spoken English, with confidence working directly across multiple teams.A self-directed and proactive communication style. You identify blockers early, make decisions in writing, and move work forward without close day-to-day management. Preferred SkillsProduction PyFlink experience, especially with the Python DataStream API and stateful jobs.Flink SQL and UDF experience.Experience migrating a live streaming pipeline or operational database to ClickHouse, including CDC or dual-write, backfill, reconciliation, rollback, and cutover.Real-time analytics, low-latency data-serving, or external/B2B data integration experience.Experience mentoring engineers and raising engineering quality through reviews.Background in real-money gaming, iGaming, fintech, adtech, or another high-volume, correctness-sensitive domain.Interest in poker or strategy games.JVM familiarity for working with thin Java connector adapters.Spark or Databricks experience for historical replay workflows.Feature-flagged rollout experience.Open-source contributions, technical writing, speaking, or relevant side projects. Benefits and SupportFully remote working environment.Equipment allowance: USD 2,000 in your first year and USD 1,000 each following year for remote-work equipment.Unlimited paid annual leave, with up to two consecutive weeks per request.12 paid sick days per year.Quarterly performance incentives: Star Performer: 50%–100% of quarterly salary. Top Performer: 10%–30% of quarterly salary.Reimbursement of recurring Deel withdrawal fees.USD 1,000 annual learning budget, with 50% reimbursement for relevant courses, certifications, and other professional development expenses. The budget resets each October and does not roll over. Equal OpportunityA5 Labs is committed to building an inclusive workplace. We welcome applicants from all backgrounds and evaluate candidates based on their skills, experience, and potential to succeed in the role.