Job Description

• Expleo is seeking two Non‑Functional Test Engineers (1 Senior, 1 Mid‑Level) to support one of our latest projects in the POS space. The successful candidates will validate the performance, stability, scalability and security of cloud‑native, device‑based and payment ecosystem components.

These roles operate across the full payments stack — covering Payment App, TMS 3.0, POS TMC, Nexo Retailer/Acquirer protocols, downstream integrations and Android POS device performance. Engineers will ensure that all systems meet enterprise‑grade Non‑Functional Requirements (NFRs) covering load, latency, resilience, device behaviour and operational integrity.

Responsibilities

• Performance & Load Testing

Define, refine and validate Non‑Functional Requirements (NFRs) Build and execute load, stress, spike, endurance and soak tests on:

SmartPOS Payment App servicesTMS 3.0 flows (downloads, commands, updates)POS TMC sync & update flowsNexo Retailer/Acquirer channelsDownstream pipelines (IPG, BAM, EventGateway, telemetry integrations)

• Measure key performance KPIs:

Transaction throughput (TPS)End‑to‑end latency (POS → IPG → EventGateway → BAM)Resource utilisation and SLA adherence

• Device‑Level Performance Testing

Validate CPU, memory, battery and thermal behaviour of Android POS devices.Assess app responsiveness:

Cold/warm start timeNetwork handover performanceLong‑running session stability

Execute 24/48/72‑hour soak tests on device builds.

• Cloud‑Native Performance & Resilience Testing

Test microservices deployed in Kubernetes and containerised environments.Validate:

Auto‑scaling & load balancing behaviourPod restart handling and resilienceCanary/blue‑green deployment performanceQueue performance (Kafka, SQS, Pub/Sub)

Execute distributed failover and recovery testing.

• Security & Compliance (Non‑penetration)

Validate TLS handshake performance, secure API headers, rate limiting and request integrity.Verify PCI‑aligned behaviour under load.Ensure logs remain free of sensitive data during stress conditions.

• Observability, Logging & Monitoring

Analyse:

Kibana/Splunk logsPrometheus/Grafana metricsCloudWatch and ELK dashboardsDistributed tracing: Jaeger/Zipkin

Detect and evaluate anomalies such as:

Error‑rate spikesThroughput dropsLatency degradationRetry or throttling behaviour

• Reporting & Governance

Produce structured NFT artefacts including:

NFT strategyPerformance test scripts (JMeter/Gatling/Locust)Execution results & KPI dashboardsRisk and bottleneck analysis

Participate in Agile/SAFe ceremonies and contribute to continuous improvement.

Qualifications

• Third level qualification in Computer Science/IT/Software Engineering

Essential skills

• Excellent client-facing skills
• Team work and emotional intelligence
• Good self-management – continuous performance is both an objective and a mind-set
• Has an innovative approach – a bold thinker and doer, matching creativity with vigilance
• High value on openness and transparency
• Excellent communication and presentations skills

Desired skills

Core NFT Tooling

JMeter, Gatling, LocustLoadRunner (optional)Android profiling tools (ADB, logcat, CPU/battery profilers)

Cloud & Infrastructure

Kubernetes (kubectl, Helm, deployments, scaling)Docker container analysisAPI Gateway performance (AWS API Gateway, Kong, Apigee, NGINX)Observability: Prometheus, Grafana, CloudWatch, ELK/KibanaUnderstanding of:

VPC networkingLoad balancers (ALB/NLB/Ingress)Redis cachingMessaging systems (Kafka, SQS, Pub/Sub)

API & Protocol Testing

REST API performanceJSON/XML payload handlingUnderstanding of Nexo Retailer/Acquirer flowsTLS, OAuth/JWT overhead analysis

Scripting & Automation

Python or BashIntegrating performance scripts into CI/CDAutomation of log parsing and KPI extraction

Payments & POS Domain Knowledge

EMV transaction lifecycleHost authorisation & settlement flowsImpact of cryptography and EMV tags on performanceAndroid POS hardware constraintsTMS flows (key loading, parameter updates, firmware updates)

Experience

• Senior NFT Engineer

  5–8+ years QA experience; 3–5+ years dedicated NFT/performance testing.2–3+ years cloud‑native performance engineering experience.Has led performance testing for distributed, microservices‑based systems.Strong experience in Kubernetes, observability stacks and large‑scale load testing.

  Mid‑Level NFT Engineer

  3–6 years QA experience; 1–2 years NFT/performance testing.Strong working knowledge of JMeter/Locust and log analysis.Familiarity with Kubernetes, microservices and cloud fundamentals.

Benefits

At Expleo, we are committed to providing a competitive salary and substantial benefits offering with unique wellbeing, financial and employee recognition programmes.

We pride ourselves on our diverse and inclusive culture and offer a variety of family friendly policies and enhanced leave to help you achieve a healthy work life balance.

By providing significant learning and development opportunities, we encourage individual growth and success throughout your career with us.

• Collaborative working environment – we stand shoulder to shoulder with our clients and our peers through good times and challenges
• We empower all passionate technology loving professionals by allowing them to expand their skills and take part in inspiring projects
• Expleo Academy - enables you to acquire and develop the right skills by delivering a suite of accredited training courses
• Competitive company benefits such as medical and dental insurance, pension, life assurance, employee wellbeing programme, sports and social events, birthday hampers and much more!
• Always working as one team, our people are not afraid to think big and question the status quo.

“We are an equal opportunities employer and welcome applications from all suitably qualified persons regardless of their race, sex, disability, religion/belief, sexual orientation or age”.

At Expleo, we understand that many people experience impostor syndrome throughout their lifetime, please do not let this discourage you from applying for this role. Our Talent Acquisition Team welcomes all CV’s and will consider your application in line with the values, requirements and role competencies.