Principal Software Engineer (POS Developer)

Job Description

Job Title : Principal Software Engineer (POS Developer)

Department : Development

Location : NASTP, Karachi Office

Job Type : Full time (on-site)

Reports To : Team Lead

Job Summary

Lead the architecture, development, and evolution of enterprise-level Android POS applications, payment engines, and device integrations. Own high‑risk transactional components such as ISO‑8583 communication, EMV workflows, and secure channel management. Mentor teams, define platform-wide standards, and ensure exceptional reliability, performance, and compliance across all POS software layers.

Key Responsibilities

Architecture & Platform Leadership

Define POS system architecture across Android, ISO‑8583 engines, device layers, security, and modular components.

Own technical decision-making for performance, scalability, and long-term maintainability.

Establish and govern engineering standards, design patterns, and code quality expectations.

Advanced Android & Kotlin Development

Lead Kotlin / Java development using Android SDK, Jetpack, WorkManager, threading, and profiling.

Oversee mission‑critical payment and offline / online flows.

Compose UI Architecture

Architect large-scale Compose UI systems following Material 3, unidirectional data flow, and state hoisting.

Optimize rendering, reduce recompositions, enforce UI performance guidelines.

ISO‑8583 & Transaction Engine Ownership

Own host communication layers including pack / unpack, MAC generation, DE mapping.

Lead all sale / void / reversal / settlement flows and ensure compliance with acquirer test suites.

Device & Hardware Integrations

Architect EMV, NFC, MSR, and printer integrations with abstraction layers.

Handle OEM SDK limitations, battery / thermal constraints, and failover strategies.

API & Ecosystem Integrations

Lead integrations for gateway, loyalty, discount, routing, onboarding, and merchant systems.

Define standards for Retrofit / Http / Ktor usage, caching, retries, and contract management.

Security & PCI DSS Compliance

Oversee PCI compliance, encryption models, secure key storage, obfuscation, secure input, and TLS.

Approve all sensitive cryptographic and security-critical implementations.

Observability & Stability Engineering

Define logging and metrics strategy; integrate crash analytics and monitoring tools.

Lead high-severity incident response, RCA, and preventive actions.

Leadership & Mentorship

Mentor senior engineers; lead design sessions and architecture reviews.

Coach teams on ISO‑8583, EMV, Compose, architecture patterns, and performance engineering.

Documentation & Governance

Maintain ADRs, API specs, architecture diagrams, test matrices, and compliance documents.

Requirements

Education :

Bachelor’s in Computer Science or related field (Master’s preferred).

Experience :

8+ years in Android / Kotlin engineering, with at least 5+ years in POS / Payments.

Proven leadership in building scalable POS platforms and payment engines.

Skills :

Advanced Kotlin, Jetpack Compose, Coroutines, Hilt, WorkManager.

Deep understanding of ISO‑8583, EMV, NFC, socket / TLS communication.

Strong architecture mindset : clean architecture, multi‑module, MVI / MVVM.

Hardware SDKs : EMV kernels, printers, scanners.

API development expertise (Retrofit / OkHttp / Ktor).

Strong Git practices, CI / CD pipelines, branching strategies.

Excellent troubleshooting, profiling, and performance optimization skills.

Nice to Have :

Backend exposure; SQL Server / EF Core understanding.

Observability stack experience (ELK, Prometheus, Firebase).

Experience with containerization and cloud deployment

Key Performance Indicators (KPIs)

KPI

Weight

Description

Architecture & Scalability

25%

Successful rollout of platform enhancements; measurable reduction in tech debt.

Protocol Accuracy & Host Compliance

20%

Pass all acquirer ISO‑8583 certification suites with ≤1% protocol defects.

Performance & Reliability

20%

≥99.7% crash‑free users; optimized RTT and

Leadership & Mentoring

15%

Positive peer feedback; uplift in team capability and code quality.

Security & PCI Compliance

10%

Zero PCI violations; strong adherence to secure coding practices.

Collaboration & Documentation

10%

High-quality cross-team communication and complete runbooks / ADRs.

Benefits

Health Insurance

Life Insurance

Professional Development Opportunities

Equal Opportunity Statement

We are an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, or disability.