Sr. Backend Engineer II - US Stocks

Founded to transform retail finance, Ajaib Group is an Indonesian fintech unicorn breaking barriers to financial access. Having recently secured a $270M Series C—the single largest funding round in Southeast Asia over the past four years—we are backed by premier global investors including Y Combinator, Ribbit Capital, SoftBank, and SBI Holdings.To build world-class products, we assemble world-class talent. Supported by our fully remote work arrangement, our team spans Eastern Europe, the Middle East, India, and Southeast Asia, allowing you to work with brilliant engineers and builders from around the globe from wherever you are. We operate with an impact-driven purpose where everyone is the owner of our customers' satisfaction. Driven by a growth mindset and a fierce will to win, we refuse to settle and constantly push engineering boundaries.Role OverviewAs a Sr. Backend Engineer II in the US Stocks team, you own backend services for trading US stocks from design to production: order flow to our brokerage partners, balances and currency conversion, market data, portfolio and corporate actions. You take on larger and more complex features, make sound design decisions under real traffic, and mentor engineers around you.Design, build and run scalable, secure backend services and APIs for trading, funding, market data and portfolio featuresOwn larger features and services end to end, including monitoring, alerting and on-call follow-upDesign for correctness first: accurate money and quantity handling, idempotent requests, safe retries and audit trailsIntegrate with US brokerage and custody partners, and make those integrations resilient to outages, delays and duplicate or out-of-order messagesBuild and improve reconciliation between our records and our partners' records, and drive root-cause fixes for mismatchesHandle US-specific events correctly, such as market hours, dividends, stock splits and settlement timingKeep services fast and stable at US market open and during volatile days, and plan capacity ahead of known eventsLead design reviews and give thoughtful code reviewsInvestigate production incidents, run root cause analysis and ship lasting fixesMentor mid-level engineers and share knowledge within the teamDesign resilient, low-latency order routing logic to manage execution across multiple Liquidity Providers (LPs) and venues, handling rate limits, partial fills, and complex order lifecyclesProactively identify systemic risks across the US Stocks domain and propose architectural improvements, acting as a technical bridge to Staff engineersRequirementsEducation: Bachelor's degree in Computer Science or equivalent practical experienceExperience: 5+ years of professional backend engineering, with a track record of owning production services under high trafficLanguages: Strong in Java, Go or another modern backend languageSystem Design: Solid understanding of microservices, REST/gRPC APIs, event-driven design, and reliability and observability practicesData & Messaging: Hands-on with relational and NoSQL databases (query tuning), caching (Redis) and messaging (Kafka)Infrastructure: Experience running services on cloud platforms (GCP or AWS), with containers and CI/CDMindset & Domain: Ownership mindset and clear communication. Experience in brokerage, trading, payments, cross-border money movement or another regulated environment is a strong plusDeep understanding of modern API-first brokerage platforms (e.g., Alpaca, Interactive Brokers) or crypto exchanges, including WebSocket streaming for market data and FIX protocol fundamentalsBenefitsPerformance Bonus - Get rewarded for the impact you makePrivate Insurance - Comprehensive health coverage for you Paid Time Off - Take the time you need to recharge and come back strongerLearning & Development - Company-sponsored training, courses, and professional certificationsHybrid Work Arrangement - Enjoy the flexibility of working both remotely and from the officeCareer Growth - Work closely with experienced leaders and take on meaningful ownership as we scaleEmployee Perks - Enjoy exclusive discounts, partnerships, and lifestyle perksCollaborative & High-Ownership Culture - Work with smart, driven people in cross-functional teams, take ownership, and make a meaningful impact for our users