Workload model from your analytics
Journeys, traffic mix, and arrival rates based on your real visitors and the peak you expect.
The Problem
Your App Was Fast in Staging Until Real Traffic Arrived
Load problems stay hidden until many people use the app at once. By then it's launch day, and the slow query or full connection pool is in production.
01 · Unknown limit
Nobody knew how many users the app could handle.
A test ramps virtual users past your expected peak to find the limit.
02 · Guesswork
Adding servers barely helped the slow checkout.
Server metrics during each run show whether CPU, database, or code is the limit.
03 · Hidden query
One unindexed query slowed every request.
Slow responses are traced to the exact query, cache miss, or connection limit.
04 · Launch day
Errors started minutes after the campaign email.
Spike tests replay a sudden traffic burst before your real campaign goes out.
Your app felt fast in staging, with 5 people clicking around. Then the launch email went out. Within minutes, checkout took 12 seconds, the API started returning 502 errors, and the database CPU hit its ceiling. Your team added servers by guesswork, and it barely helped, because the real problem was one unindexed query. Nobody knew how many users the app could handle until it stopped handling them.
We start with your traffic: analytics, past peaks, and the campaign you're planning. We script the journeys that matter in k6 or JMeter, ramp virtual users past your expected peak, and watch server metrics during every run. Each slow response gets traced to its cause: a query, a cache miss, or a connection limit. You learn your breaking point in a test, not on launch day.
Traffic modeled from analytics
Virtual users follow the paths real visitors take, at the pace your peaks actually reach.
Percentiles, not averages
p95 and p99 response times show what your slowest users feel, which averages hide.
Bottlenecks traced to a cause
Server metrics during each run point to the query, cache, or limit behind every slowdown.
Our Performance Testing Services Process
From Traffic Model to Capacity Plan in Five Clear Steps
You approve the traffic model and the pass or fail targets before any test runs, and every result comes with the server metrics that explain it.
We review your architecture, hosting, and analytics, plus the event you're preparing for. You get the journeys to test, a target peak, and a fixed price before any scripts are written.
What's Included
What You Get With Our Load Testing Services
Everything needed to know your app's limits before your users find them: a traffic model, scripted journeys, load and stress runs, bottleneck analysis, and a retest.
Compare Options
DeveloperLook vs a DIY Load Tool vs Adding Bigger Servers
A DIY load tool is cheap if someone knows how to model traffic, and bigger servers buy time. Here's how a performance testing company compares when you need answers before a launch.
| Feature | DeveloperLookBest fit | DIY tool | Bigger servers |
|---|---|---|---|
| Traffic model | Built from your analytics | Whatever the script guesses | No model, just capacity |
| Test types | Load, stress, spike, and soak | Usually one load run | |
| Reading results | Percentiles tied to server metrics | Charts without a cause | Found out in production |
| Root cause | Query, cache, or limit named | Often left to guesswork | Hidden by extra hardware |
| Speed to answer | 1 to 2 weeks | Fast if you know the tool | Minutes to scale up |
| Retesting | Same test rerun after fixes | Up to your team | |
| Ownership | Scripts stay in your repo | Yours | Tied to a bigger hosting bill |
| Cost | Fixed price from $850 | Free open-source tools | Higher hosting bill every month |
DeveloperLook
DIY tool
- Traffic model
- DeveloperLook: Built from your analyticsDIY tool: Whatever the script guesses
- Test types
- DeveloperLook: Load, stress, spike, and soakDIY tool: Usually one load run
- Reading results
- DeveloperLook: Percentiles tied to server metricsDIY tool: Charts without a cause
- Root cause
- DeveloperLook: Query, cache, or limit namedDIY tool: Often left to guesswork
- Speed to answer
- DeveloperLook: 1 to 2 weeksDIY tool: Fast if you know the tool
- Retesting
- DeveloperLook: Same test rerun after fixesDIY tool: Up to your team
- Ownership
- DeveloperLook: Scripts stay in your repoDIY tool: Yours
- Cost
- DeveloperLook: Fixed price from $850DIY tool: Free open-source tools
Projects We've Built
News, Booking, and Trading Products We Have Built
News, food delivery, travel booking, and trading products our team designed and built. Products like these face traffic spikes from breaking news, dinner rushes, and launches.
Deus News and Magazine Website Design and Development
- News & Media
- Website
Sevanor Food Delivery App and Restaurant Dashboard
- Food & Beverage
- Food Delivery
- Dashboard
NFTIN NFT Marketplace App and Trading Dashboard
- Crypto & NFT
- Dashboard
- Mobile App
HoliNest Travel Booking Website and Dashboard
- Travel
- Vacation Rental
- Booking System
What Our Clients Say
What Clients Say After Launch
Feedback from teams we have designed and built web and mobile products for.
We had a pretty specific idea of what we wanted our website to become, but I wasn’t sure how easily we could explain all of it to a development team. There were quite a few moving parts, and we were working toward a deadline, so I expected a few things to get lost along the way. That never really happened. They understood what we were trying to achieve, kept us updated throughout the process, and got everything ready within the agreed timeline. The final site feels much easier to navigate, works beautifully on mobile, and is noticeably smoother for our customers. It was a huge relief seeing the original idea actually turn into the website we had in mind.
The mobile experience is probably my favourite part of the new site. We had spent a lot of time making sure the desktop version looked right, and the team kept pushing us to think about how everything would actually feel on a phone too. They were right. The navigation is clean, the interactions feel natural, and everything we’ve tested so far works exactly as it should. They also went through the links, forms, integrations, and other details more than once before launch, which I really appreciated. And even after going live, we could still reach out when something came up. The whole process felt friendly, organised, and surprisingly straightforward.
What I appreciate most is that the website is actually easy for us to manage now. We can update content ourselves instead of sending a developer a message every time we need to change something small. They also paid attention to the technical SEO side, which mattered to us because we didn’t want a new website to create problems for the traffic we already had. I’ve probably asked more questions than I should have since launch, but every question has been handled patiently and without any fuss. The team is easy to work with, they explain things clearly, and when we need something changed, they focus on getting it done rather than making the process complicated.
1,250+
Projects shipped
10+
Years of experience
Top 3%
Upwork Top Rated Plus
5 stars
Average review score
Want results like these?
Tell us what you are building. You get a reply within 24 hours on business days, then a written estimate.
Work Culture
Why Teams Trust Us With Their Launch-Day Traffic
Load tests mislead when the traffic is unrealistic or the results lack a cause. These habits keep our numbers honest and useful.
Realistic traffic, not hammering
We model journeys with think times and a real traffic mix. Hitting one URL in a loop makes nice charts and tells you very little.
Production-like environments
We test on staging sized like production, or in an agreed production window. Results from a tiny staging server don't predict launch day.
Safe test windows
We agree on limits, alerts, and a stop switch before any test touches shared infrastructure. Third-party APIs are mocked when their terms forbid load tests.
Plain answers on capacity
You get a number you can plan with: how many users your setup handles and where it breaks. If more servers won't help, we'll say so.
Same test, before and after
We rerun the identical scenario after every fix. That's the only fair way to show a change helped, instead of guessing from a different test.
Scripts in your repository
Every k6 or JMeter script and dashboard stays with you. Rerun them before the next launch without paying us again.
Overview
How do performance testing services work?
DeveloperLook provides performance testing services for web apps, APIs, and online stores before launches and traffic spikes. We model your real traffic, run load, stress, and spike tests in k6 or JMeter, and trace each slowdown to its cause. Baseline load tests start at $850 and take 1 to 2 weeks.
DEVELOPERLOOK
Project facts · Performance Testing Services
- Service
- Performance Testing Services (workload model, load and stress tests, bottleneck analysis, retest)
- Typical timeline
- 1 to 2 weeks for a baseline test, 3 to 5 weeks for a capacity program
- Platforms
- Web apps, REST and GraphQL APIs, online stores, and mobile app backends
- Built with
- k6, Apache JMeter, Gatling, Grafana, New Relic, and Datadog
- Experience
- 10+ years of development experience and 1,250+ shipped projects
- Post-launch support
- 14 days of retest support after the report, 30 days on larger plans
- Communication
- Calls in US, UK, and AU business hours
- Starting price
- From $850 USD, fixed scope after a free load review
Reviewed 8 Oct 2026 by Saimul Islam
Good fit
Teams before a launch or sale
Your product launch or Black Friday sale is 6 weeks out, and you need load testing services that show whether checkout holds at peak.
SaaS teams signing bigger customers
You're onboarding a customer 10 times your usual size and want software performance testing before their users log in.
Apps that slow down at peak hours
Your app gets slow every weekday at 9am, and you need someone to trace whether the database, cache, or code is the limit.
Teams moving to new hosting
You're migrating to new hosting or Kubernetes and want load and performance testing services to prove the new setup is faster.
Agencies with high-traffic clients
Your agency's client has a big campaign coming, and you want a load testing company to test their site under your brand first.
Not a fit
Page speed scores only
You want better Lighthouse or Core Web Vitals scores for a single visitor, not capacity under load. Our Website Speed Optimization page covers that.
Features still broken
Your app still has broken features. Fix those first with our Software Testing Services, because a load test on a buggy build wastes the run.
Phone smoothness concerns
Your concern is scrolling and launch speed on phones, not server load. Our Mobile App Testing Services page covers on-device performance.
Budget under $850
Your budget is under $850. Run a free k6 script against one key page on staging, and watch your server's CPU and database while it runs.
Not sure we're the right fit?
Book a free call or message us. We'll tell you honestly whether we're the right team.
Pricing
Transparent Starting Prices for Performance Testing Services
These are starting points in USD. Your final price depends on the number of journeys, the test types, and your environment, and you get a fixed proposal after a free load review.
For apps that need to know whether their key journeys hold up at the expected peak.
$850one-time, USD
- Up to 2 user journeys scripted in k6
- Load test to 2X your expected peak
- p95 and p99 response times and error rates
- Server metrics read during the run
- Report naming the top 5 bottlenecks
- 14 days of retest support after the report
Recommended
For launches and sales that need the real breaking point found and fixed before the date.
$2,100one-time, USD
- Everything in Baseline Load Test
- Up to 5 journeys in k6 or JMeter
- Stress and spike tests to the breaking point
- Database query and cache review
- 1 retest after your fixes
- 30 days of retest support after the report
For growing products that need a capacity plan and performance checks on every release.
$4,300one-time, USD
- Everything in Load and Stress Test
- 4-hour soak test for memory leaks
- Capacity plan: users per server size
- Fixes for the top 3 bottlenecks
- Performance thresholds in your CI pipeline
- 30 days of retest support after the report
For Agencies
White-Label Load Tests for Agencies and Studios
You own the client relationship. We load test your clients' sites and apps before their big campaigns, under your brand, so traffic spikes don't turn into emergency calls. Results arrive as a branded report you can present.
How the partnership works
White label: your client only ever sees your brand
- Your client
- You, the agency
- DeveloperLook
Share the campaign
Send the site, the expected traffic, and the date your client goes live.
- Client needs
- You share the details
- Details received
We test the limits
We model traffic, run the tests, and trace any bottlenecks we find.
- Scope and plan
- Proposal to resell
- Your quoteYOUR LOGO
You brief the client
Present the capacity report and fixes under your agency's name.
- Done by our team
- Your brand on it
- Handed to your clientDone
Partner with DeveloperLookDelivered under your brand
Branded capacity reports
Results and bottlenecks presented under your agency's name.
Fewer emergency calls
Find the limits before the campaign instead of during it.
Booked around campaigns
Testing scheduled ahead of each client launch or sale.
Fix help available
We can tune queries and caching when your team is stretched.
The Right Technology for Your Project
Technology Stack
We use open-source load tools and the monitoring you already run, so every result can be rerun and explained.
- k6
- Apache JMeter
- Gatling
- Locust
- Grafana
- Prometheus
- New Relic
- Datadog
AWS
Docker
Kubernetes- Cloudflare
- GitHub Actions
- GitLab
Slack- Jira
FAQ
Frequently Asked Questions
Straight answers on load and stress tests, costs, timelines, and who should run them.
Saimul IslamFounder & CEO, DeveloperLookStill have questions?
Send a message or book a call with the team.
A baseline load test from DeveloperLook starts at $850 and covers up to 2 user journeys. A Load and Stress Test with up to 5 journeys and a retest starts at $2,100, and a Capacity and Soak Program with fixes starts at $4,300. Your fixed price comes after a free load review.
A baseline load test takes 1 to 2 weeks, including the traffic model, scripts, test runs, and report. A full capacity program with soak tests and fixes takes 3 to 5 weeks. Book it at least a month before a launch or sale, so there's time to fix what the test finds.
Performance testing is measuring how fast and stable a system stays under a given workload. It's an umbrella term. A load test checks expected traffic, a stress test pushes past it, and a spike test simulates sudden bursts. A soak test runs for hours to catch memory leaks, so each type answers a different question about your app.
Software performance testing applies those checks to an application's code and infrastructure: response times, throughput, error rates, and resource use under load. Our software performance testing services also read server metrics during each run, so a slow endpoint gets traced to the query or setting behind it.
Load testing is simulating the number of users you expect, at the pace they arrive, to see how your app responds. Virtual users follow scripted journeys like login, search, and checkout. You learn whether response times and error rates stay within your targets at peak.
In software, load testing means running scripted traffic against an application or API with a tool like k6, JMeter, or Gatling. The tool records response times for every request while monitoring shows CPU, memory, and database load. Comparing the two shows which part of the system gives out first.
Performance testing is important because slowdowns and outages hit exactly when the most people are using your app. A launch, a sale, or a press mention brings the traffic, and an untested system can fail in front of all of it. Testing first turns that risk into a known number.
Load testing before a launch tells you your breaking point while there's still time to fix it. Without a test, the first real measure of capacity is launch day itself. A test a few weeks early leaves room to add an index, tune a cache, or resize servers on your schedule.
Load testing is done by performance engineers, QA teams with performance skills, or an outside load testing company. It takes someone who can model traffic, script journeys, and read server metrics, which most product teams don't have in-house. At DeveloperLook, the engineers who run the test also help fix the bottlenecks.
Load testing is done in 5 steps, from a traffic model to an analysis of the results. We model the traffic, script the user journeys, ramp virtual users to the target load, and monitor the servers during the run. The key is ramping gradually, so you see where response times start to bend, not just whether the app survived.
Saimul IslamFounder & CEO, DeveloperLookStill have questions?
Send a message or book a call with the team.
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