Juspay is a multinational payments technology company headquartered in Bangalore, founded in 2012 and now powering payments for more than 500 leading global enterprises and banks. The scale is the defining fact of engineering here: over 300 million transactions a day, an annualized total payment volume above $1 trillion, and a reliability target of 99.999%. A global team of 1200+ payment experts spans Bangalore, San Francisco, Dublin, Sao Paulo, and Singapore, building a modular product suite that covers payment orchestration, authentication, tokenization, fraud and risk management, payouts, reconciliation, and payment analytics.
This backend software development engineer role exists inside Juspay's Centres of Excellence, each of which deliberately balances Framework Development, described internally as the ideal, with Business Enablement, the practical. On the backend track you'll own the business logic that handles constantly evolving payment requirements across UPI, integrations, and authentication, and you'll express genuinely complex payment flows concisely. Juspay is the biggest functional programming company running its entire business logic in FP, so this is a role for engineers who want to architect frameworks in deep functional languages rather than assemble CRUD services.
You'll work alongside the other centres of excellence and draw on their output daily. The SDK teams build frictionless one-click payment experiences and native payment pages, including React markups inside Presto, Juspay's proprietary UI framework. The data science group turns intelligence from over a billion transactions into intelligent traffic routing, self-healing systems, automatic anomaly detection, and AI-powered payment operations. The infrastructure group runs multi-DC architecture, an infrastructure DSL for unified management at scale, and distributed computing on edge devices.
Your first three to six months start at what Juspay calls Day0: you hit the ground running on mission-critical projects and next-generation framework development rather than warming up on peripheral work. Expect to build fluency in the functional programming stack, take on API integrations, and start meeting reliability and performance problems that only appear at large scale. You'll also be exposed to merchant-facing operations, where the standard is managing merchants both big and small with zero issues.
The growth path here is anchored in first-principles thinking, with the stated intention that engineers progress into skilled system architects, following the trajectory of the DUI/Hyper SDK team. You'll learn from strong engineers on hard problems, with room to move toward low-code and no-code platform work that streamlines and accelerates application development for end users.
Responsibilities
✓Design and build backend business logic that handles evolving payment requirements across UPI, integrations, and authentication
✓Express complex payment logic concisely using functional programming, within a codebase built entirely on FP principles
✓Architect and extend internal frameworks that balance long-term design ideals with immediate business enablement needs
✓Build and maintain API integrations with payment service providers, banks, and merchant systems at production scale
✓Solve reliability and performance problems that emerge specifically at high transaction volume and low latency budgets
✓Contribute to low-code and no-code platform capabilities that accelerate application development across teams
✓Support self-service features that let end users modify and customize their applications without engineering intervention
✓Collaborate with SDK, data science, and infrastructure teams to deliver end-to-end payment flows reliably
✓Uphold operational standards for merchants of every size, working toward zero-issue payment processing
Who You Are
✓Strong programming fundamentals with the ability to reason about correctness, types, and abstraction in backend systems
✓Genuine enthusiasm for architecting frameworks using deep functional programming languages rather than conventional imperative stacks
✓Interest in solving reliability and performance problems that surface at very large transaction scale
✓Solid understanding of API design, integration patterns, and how backend services communicate in distributed systems
✓Ability to model complex, changing domain logic clearly, keeping implementations concise and maintainable over time
✓Comfort working from first principles on ambiguous problems rather than following prescribed implementation patterns
✓Willingness to work on mission-critical production systems where availability targets are measured in five nines
✓Based in or willing to relocate to Bangalore for this full-time, on-site engineering role
Nice-To-Haves
✓Hands-on experience with Haskell, PureScript, Scala, or another statically typed functional language
✓Prior exposure to payments, fintech, UPI flows, or payment gateway and PSP integrations
✓Experience building developer platforms, DSLs, or internal frameworks used by other engineering teams
✓Familiarity with distributed systems concepts such as multi-datacenter architecture and fault tolerance
✓Interest in low-code or no-code tooling and self-service configuration platforms
About Juspay Technologies
Juspay is a leading multinational payments technology company that powers superior conversion rates, seamless customer experiences, cost optimization, and fraud reduction at scale for over 500 top global enterprises and banks. Founded in 2012 and headquartered in Bangalore, India, Juspay processes more than 300 million daily transactions with an annualized total payment volume exceeding $1 trillion at 99.999% reliability. Its global network of 1200+ payment experts operates across San Francisco, Dublin, Sao Paulo, and Singapore. Juspay offers a modular, interoperable product suite spanning open-source payment orchestration, authentication, tokenization, fraud and risk management, global payouts, reconciliation, and unified payment analytics, plus white label payment gateway and real-time payments infrastructure for banks.
