Senior Software Engineer
Engineering • Bangalore, India (Hybrid) • Full-Time
Mission-Critical Core Banking Platform • Cloud-Native • Low-Latency Transaction Processing
ACI Worldwide is seeking a Senior Software Engineer to join the team building and operating a mission-critical, low-latency core banking platform. Our product is architected cloud-natively and containerized from the ground up, deployed initially on Microsoft Azure / AKS with a clear roadmap to Red Hat OpenShift, AWS, and Google Cloud Infrastructure (GCI). Every design decision — from threading models to deployment topology — is made with high throughput, sub-millisecond latency, and five-nines availability in mind.
This is a full-stack engineering role in the deepest sense: you will design and build features end to end, own the reliability and performance of what you ship, actively contribute to the CI/CD pipeline and quality strategy, and provide L3 production support when the platform counts on it. We are also on an active modernization journey, migrating mission-critical COBOL logic to modern Java services, and your ability to read, understand, and translate legacy COBOL will be highly valued.
We are looking for self-motivated, driven engineers who take pride in craftsmanship, embrace AI as an accelerator across the full development lifecycle, and are genuinely excited to grow their careers at ACI Worldwide.
Location: Bangalore , India
Work Model: Hybrid — on-site on designated days; remote-eligible on other days per team and business needs
1) Low-Latency Application Engineering
Design, implement, and optimize high-performance Java services for real-time transaction processing: payments, authorization, clearing, and settlement workflows where latency and correctness are non-negotiable.
Apply deep JVM knowledge — threading models, garbage collection tuning, lock-free data structures, and async I/O — to sustain predictable throughput under peak load.
Define and enforce performance budgets: author benchmarks, regression tests, and latency SLOs; profile and root-cause regressions before they reach production.
Build against modern cloud-native patterns: microservices, event-driven messaging (NATS), reactive pipelines, and 12-factor application design.
2) Cloud-Native & Container-First Development
Write software that is container-native from day one: images must be lean, stateless where possible, and fully operable on Kubernetes (AKS, OpenShift, EKS, GKE).
Collaborate with the DevOps/Platform team on Kubernetes manifests, Helm/Carvel packaging, resource requests/limits, health probes, and rolling deployment strategies.
Understand and contribute to GitOps workflows; ensure application configuration is version-controlled, auditable, and environment-agnostic.
Design for multi-cloud portability from the start: avoid cloud-vendor lock-in in application code and dependency choices.
3) AI-Augmented Development Lifecycle
Leverage AI tools actively across the SDLC: AI-assisted code generation and review, test case synthesis, documentation drafting, defect analysis, and performance diagnostics.
Apply responsible AI practices: validate all AI-generated output for correctness, security, and maintainability before merging; never place secrets, PII, or PCI data into AI prompts.
Contribute to team-level AI adoption: share effective patterns, prompt strategies, and tooling discoveries that raise the velocity and quality bar for the whole team.
Stay current with AI/ML advancements relevant to banking — intelligent anomaly detection, automated triage, fraud signal enrichment — and propose production-ready applications.
4) Quality Engineering & Test Automation
Own quality for what you ship: write comprehensive unit, integration, and contract tests; enforce non-negotiable coverage thresholds and quality gates in CI.
Author and maintain end-to-end test scenarios for transaction processing flows; partner with Quality Engineering to integrate Testkube-orchestrated test suites into the pipeline.
Practice shift-left quality: treat a bug escaping to staging as a process failure, not an expected outcome.
Participate in code reviews with a quality lens: correctness, edge cases, error handling, observability hooks, and long-term maintainability.
5) Security & Compliance
Write secure-by-design code in regulated financial environments: input validation, output encoding, least-privilege service identities, and safe secret consumption via ESO/vault integrations.
Ensure compliance controls are built into the code — not bolted on afterward: PCI-DSS, SOC2, and audit logging requirements are first-class acceptance criteria.
Participate in threat modeling sessions, security code reviews, and SAST/DAST remediation cycles; treat security findings with the same urgency as production incidents.
6) DevOps Collaboration & Engineering Excellence
Engage actively with the DevOps/Platform team: contribute to pipeline definitions, own your service’s observability (structured logs, metrics, distributed traces), and participate in on-call rotations.
Write and maintain runbooks, deployment guides, and architecture decision records (ADRs); documentation is a deliverable, not an afterthought.
Champion engineering best practices: clean code, SOLID principles, API contract discipline, backward compatibility, and disciplined release management.
7) COBOL Modernization Support
Read and interpret existing COBOL programs to extract business logic, data flow, and processing rules that must be faithfully reimplemented in modern Java services.
Collaborate with domain experts and architects to validate that modernized Java implementations are behaviorally equivalent to legacy COBOL counterparts under all documented business scenarios.
Document COBOL-to-Java translation decisions, edge cases, and business rule interpretations to build institutional knowledge for the long-term migration program.
8) L3 Production Support
Serve as the third line of escalation for production issues on services you own: diagnose complex failures using logs, metrics, traces, and thread/heap dumps.
Deliver timely, accurate root-cause analyses and post-incident reviews; implement durable fixes and preventive controls to eliminate recurrence.
Maintain a “you build it, you run it” mindset: production reliability is a shared engineering accountability, not a handoff.
8+ years of professional software engineering experience; substantial time building production systems that handle high-volume, low-latency workloads.
Java — expert-level proficiency: JVM internals, concurrency, performance tuning, Spring Boot / Spring ecosystem, and modern Java (17+) features.
Low-latency systems — demonstrated experience designing and optimizing transaction processing, payments, or equivalent high-throughput distributed systems.
Microservices & APIs — RESTful and event-driven service design; experience with API versioning, backward compatibility, and contract testing.
Containers & Kubernetes — hands-on experience containerizing Java applications and running them on Kubernetes (AKS, EKS, GKE, or OpenShift).
Cloud platforms — Azure (primary); working familiarity with AWS or GCI a strong plus.
CI/CD & DevOps — experience with Jenkins, Gradle, container image builds, and automated quality gates; comfortable contributing to pipeline definitions.
Test automation — strong unit, integration, and e2e testing discipline; experience with JUnit 5, Mockito, Testcontainers, or equivalent.
Security — secure coding practices in regulated environments; familiarity with OWASP Top 10, input validation, and secrets management.
Observability — structured logging, metrics (Micrometer/Prometheus), and distributed tracing (OpenTelemetry or equivalent).
Databases — PostgreSQL (or equivalent relational DB) in production; familiarity with schema migration, query optimization, and connection pooling.
AI-assisted development — active use of AI coding tools (Copilot, Claude, Cursor, or equivalent) with disciplined validation practices.
Banking or payments domain experience : core banking, payment processing, ACH, SWIFT, card authorization, or clearing & settlement. Understanding of 8583 , 20022 specs and implementations based on it
Drools / rule engine experience : authoring and maintaining business rules in Drools (KIE) or a comparable BRMS; ideally applied to transaction routing, risk, or eligibility logic.
NATS messaging : operational experience building event-driven services on NATS or equivalent (Kafka, Pulsar, RabbitMQ).
Multi-cloud portability : experience deploying identical workloads across two or more of Azure, OpenShift, AWS, and GCI.
COBOL literacy — ability to read and interpret COBOL programs sufficiently to extract and translate business logic into Java.
Carvel toolchain : familiarity with ytt, kapp-controller, or imgpkg for Kubernetes-native packaging and GitOps.
Regulated environment experience : PCI-DSS, SOC2, GDPR, or equivalent compliance frameworks embedded in engineering practices.
AI/ML feature delivery : experience shipping AI or ML capabilities as part of a production product (anomaly detection, intelligent routing, fraud signals, etc.).
Technical mentorship : demonstrated experience upleveling junior engineers through code review, pair programming, or structured coaching.
Technically challenging work on a platform that processes mission-critical banking transactions for global financial institutions.
A cloud-native, automation-first engineering culture that invests in quality, security, and developer experience as competitive advantages.
Real career growth: ACI actively develops engineers into senior technical leaders and engineering managers; your trajectory here is yours to define.
An AI-forward team that embraces modern tooling and gives engineers the latitude to experiment, improve, and lead.
Competitive compensation and benefits package; hybrid flexibility
#LI-AP
ACI Worldwide is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, national origin, disability, or veteran status.
ACI Worldwide is a global leader in mission-critical, real-time payments software . Our proven, secure and scalable software solutions enable leading corporations, fintechs and financial disruptors to process and manage digital payments , power omni-commerce payments , present and process bill payments , and manage fraud and risk . We combine our global footprint with a local presence to drive the real-time digital transformation of payments and commerce.
