Performance Engineering

Faster Apps.
Measurable Results.

We identify and eliminate the bottlenecks slowing your product down — from database query plans to API latency to frontend load times. Every engagement comes with before/after benchmarks.

DB Query Tuning API Latency Reduction Core Web Vitals Load Testing Cache Strategy
Performance Report
Before vs After Optimisation
API Response
68ms 1.2s
94% faster
Page Load
0.9s 6.4s
86% faster
DB Query
12ms 890ms
98% faster
Lighthouse
97 41
+56 points
Performance Score
97 / 100
10× Faster
Zero Regressions
10×
Avg Speed Improvement
98%
DB Query Reduction
97+
Avg Lighthouse Score
40%
Avg Infrastructure Cost Saved
What We Optimise

Full-Stack Performance Optimization

Every layer of your application stack — from database to browser — profiled, benchmarked, and optimised for maximum speed.

Database Performance Tuning
Query profiling, index optimisation, N+1 elimination, connection pooling, read replica setup, and query plan analysis. We turn 2-second DB calls into 10-millisecond ones.
Query PlansIndexesRead Replicas
API & Backend Optimization
Profiling API endpoints, eliminating redundant calls, implementing response caching (Redis), payload compression, async processing, and connection keep-alive strategies.
RedisAsyncProfiling
Frontend & Core Web Vitals
LCP, FID/INP, and CLS improvements — image optimisation, code splitting, lazy loading, critical CSS extraction, bundle size reduction, and CDN configuration.
Core Web VitalsBundle SplitCDN
Load Testing & Capacity Planning
Realistic load simulation with k6, JMeter, or Locust — identify breaking points before users do. Accompanied by capacity planning recommendations and autoscaling tuning.
k6JMeterLocust
Infrastructure Right-Sizing
CPU and memory profiling of running services — identify overprovisioned resources, move to appropriate instance types, and reduce cloud bills without sacrificing performance.
CPU ProfilingMemoryCost
Mobile App Performance
Frame rate optimisation, startup time reduction, memory leak detection, network request batching, and offline caching strategies for iOS and Android applications.
60fpsCold StartMemory
Tools We Use

Profiling & Optimization Tools

Redis PostgreSQL EXPLAIN MySQL Performance Schema k6 Load Testing Prometheus Grafana Jaeger Tracing Elastic APM Redis PostgreSQL EXPLAIN
Lighthouse CI Postman Monitors New Relic Datadog APM WebPageTest React Profiler Chrome DevTools Lighthouse CI Postman Monitors
Our Approach

Data-Driven Performance Engineering

We don't guess — we profile. Every recommendation is backed by traces, flame graphs, and before/after benchmarks you can verify independently.

Profile Before Optimising
Distributed tracing and flame graphs pinpoint the exact bottleneck. We fix the 20% of code causing 80% of the slowness — not arbitrary rewrites.
Benchmark Every Change
Every optimisation is validated with before/after load test results. You see the numbers, not just our word for it — p50, p95, p99 response times documented.
No Breaking Changes
All optimisations are made with zero change to API contracts or user-facing behaviour. Regression test coverage is expanded, not reduced.
🔍
N+1 Query Elimination
DataLoader, eager loading, and query batching — the most common cause of catastrophic database performance solved systematically.
💾
Multi-Layer Caching
CDN, HTTP cache headers, Redis application cache, and query result cache — the right cache at every layer of the stack.
📦
Bundle Optimisation
Code splitting, tree shaking, lazy imports, and dynamic loading cut JavaScript bundle sizes by 60–80% on average.
🗄️
Index Strategy
Composite indexes, partial indexes, and covering indexes designed from actual query patterns — not guesswork.
Async Offloading
Move heavy operations to background workers — email sends, image processing, reports — so API responses return immediately.
📊
Continuous Monitoring
Post-optimisation alerting on p99 latency regressions — so performance gains don't erode as the codebase evolves.
Why Appther

Why Teams Choose Appther for Performance

We've fixed performance problems in production systems handling millions of users — from fintech APIs to healthcare platforms to consumer apps.

01
Before/After Benchmarks
Every engagement ends with a documented performance report — p50, p95, p99 response times, Lighthouse scores, and database query times measured before and after.
02
2-Week Turnaround
Our performance sprints are focused and time-boxed. Most engagements deliver significant improvements within 2 weeks — you see results fast.
03
Zero Feature Risk
Optimisations are applied in isolation with full regression test coverage. No features are changed, no API contracts broken — pure performance gains.
04
Knowledge Transfer
We explain every change we make and why — so your team understands the patterns and can maintain performance as the codebase grows.
05
Lower Infrastructure Bills
Faster code needs less compute. Performance improvements typically reduce cloud spend by 30–50% — the project often pays for itself in months.
06
Full-Stack Coverage
Frontend, API, database, and infrastructure — we profile the entire stack and fix root causes, not symptoms.
Our Process

From Bottleneck to Blazing Fast

A systematic 5-phase approach that finds the real problems and fixes them with measurable results.

1
Baseline Audit
Profile current performance — establish p50/p95/p99 baselines, identify slow endpoints, queries and pages.
2
Root Cause Analysis
Distributed traces, flame graphs and query plans pinpoint the exact bottlenecks causing slowness.
3
Prioritise & Plan
Rank optimisations by impact vs effort. Agree on scope, expected improvements, and success criteria.
4
Implement & Test
Apply optimisations in branches — validated by load tests and regression suites before merging.
5
Report & Monitor
Deliver before/after performance report, set up ongoing alerting, and hand over to your team.
FAQ

Frequently Asked Questions

How much faster will our app get?

Results depend on how poorly optimised the current state is. Our typical engagements achieve 5–20× improvement in the slowest endpoints, 50–95% reduction in database query times, and Lighthouse scores improving from 40–60 to 90+. We set realistic expectations after the baseline audit.

Will performance optimisation break existing functionality?

No — all optimisations are implemented in isolated branches with full regression test coverage before merging. We expand the test suite as part of the engagement and use feature flags for higher-risk changes. Zero tolerance for regression is a core delivery requirement.

What causes most application performance problems?

The most common causes we encounter: (1) N+1 database queries hidden in ORM abstractions, (2) Missing or incorrect database indexes, (3) No caching layer between the application and database, (4) Synchronous processing of tasks that should be asynchronous, (5) Unoptimised JavaScript bundles. These five issues account for 80%+ of performance problems we fix.

Do you work on mobile apps as well as web?

Yes. We optimise React Native and Flutter apps for startup time, frame rate, network efficiency, and memory usage, as well as native iOS and Android applications. Mobile performance engagements typically include profiling with Xcode Instruments or Android Profiler alongside backend API optimisation.

How long does a performance optimisation engagement take?

A focused performance sprint typically runs 2 weeks — baseline profiling in week 1, implementation and validation in week 2. Larger engagements covering the full stack (frontend, API, database, and infrastructure) take 4–6 weeks. We provide a timeline and scope after the initial audit call.

What is the cost of performance optimisation?

A focused 2-week performance sprint starts from $8,000. A comprehensive full-stack performance engagement covering frontend, API, database, and infrastructure typically ranges from $15,000–$40,000. Given that performance improvements frequently reduce infrastructure costs, engagements often have a clear ROI within months.

Get Started

Is Your App Slow? Let's Fix It.

Share your slowest endpoints and we'll do a free 30-minute performance review — identifying quick wins and estimating the improvement potential. No commitment required.

Free Baseline Audit Before/After Report Fixed-Price Sprints Zero Regressions