Choosing an eCommerce development company starts with one question most vendors skip: should this be built at all, or does a platform already do it? Once the answer is "build", the checks that separate a good eCommerce development company from an expensive one are specific: experience with multi-vendor order routing and B2B pricing logic, how they handle payments, tax and currency across jurisdictions, which ERPs and fulfillment systems they have integrated with, whether they can ship the same day during your peak season, and whether the engineers on the first call will still be on the account in year three. This guide lists nine checks, the red flags, and a 30-minute call script, drawn from building Nautical Commerce, Greek House and other commerce platforms.
Check 1. They tell you when not to build
B2C commerce is a solved design problem: add to cart, enter card, receive package. If that is the whole product, a good vendor will say so and point you at Shopify or a comparable platform, because custom code there is money spent on a problem someone else already solved.
Custom engineering starts paying for itself when the business logic exceeds what templates support: customer-specific pricing tiers, quote-to-order workflows with approval chains, net-30/60/90 terms, multi-vendor catalogs, group ordering, licensing rules on what may be sold to whom. Ask the vendor to describe a project they turned down or steered to an off-the-shelf platform. A company that has never said "do not build this" will not say it to you either. The B2B eCommerce development page describes where the line usually falls.
Check 2. Marketplace and B2B logic they have shipped before
Multi-vendor marketplaces are the hardest commerce architecture to get right. Each vendor has its own catalog, pricing, fulfillment process and payout schedule, so the platform has to handle vendor onboarding, product normalization across vendors, order routing (which vendor fulfills which line item), commission calculation, multi-party payment splitting, return and refund routing back to the right vendor, and consolidated reporting for the operator.
B2B portals have their own list: per-customer pricing, bulk ordering, quote requests, approval chains, credit terms and catalog permissions where some buyers see products others do not. Ask which of these the vendor has built and on what platform. On Nautical Commerce, a marketplace-as-a-service platform backed by a $30M Series A, seven EltexSoft engineers extended a one-year-old Django and React codebase with payment processor integrations, custom fee structures, multi-currency and multi-language support, and tax calculation across jurisdictions, on a platform processing more than 200,000 transactions a month.
Check 3. Payments, tax and currency are engineering, not configuration
Multi-party payouts, multi-currency pricing, tax across jurisdictions and time zones interact in ways that are easy to get wrong and expensive to fix after launch. A vendor who has done this will insist on whiteboarding the money flow before writing code: who is the merchant of record, where Stripe Connect or an equivalent sits, how refunds unwind a split payment, when tax is calculated and by which service, and what stays out of PCI scope.
Ask for the diagram. If the answer is "we will use a plugin", the plugin will decide your business rules for you.
Check 4. Integrations with the systems that run the business
Commerce platforms rarely stand alone. Orders flow into ERPs (SAP, NetSuite, custom), CRMs, production partners, warehouses and shipping aggregators, and the hard part is customized or non-standard goods. On Greek House, a custom apparel platform for fraternities, sororities and student organizations, routing orders from the website into Salesforce was one of the most complex parts of the engagement: every order carried design selections, size matrices, embroidery or print specifications and college licensing attributes, and all of it had to arrive clean for order management and production coordination.
Ask which systems the vendor has integrated with, what the data model looked like, and what broke. The second answer tells you more than the first.
Check 5. Release process: can they ship the same day in peak season
Commerce businesses have peaks: rush season, Black Friday, a campaign launch. The question is not whether the vendor can build features but whether they can deploy a fix at 11am and have it in production by the end of the day when revenue depends on it.
That capability comes from infrastructure set up before features: CI/CD, automated tests, staging environments, the ability to ship on demand. When Greek House came to EltexSoft at the end of 2022, the previous team had slowed releases to once every few months. The first work was not a feature; it was CI/CD and staging. During rush season the team then shipped within 24 hours of scope, and the company stayed on the Inc. 5000 list across multiple years through its 2024 acquisition. Ask any vendor for their deployment frequency on a live client and whether that client can request a same-day release.
Check 6. Scale and enterprise readiness
If you sell to enterprise buyers, they evaluate your security posture before your features; if it fails, they never see the features. SOC 2 readiness, separate customer environments, audit logging and a documented incident process are table stakes for a commerce platform with business customers. For consumer volume, ask about load testing, caching strategy, catalog performance at your SKU count and how the platform behaves when a vendor uploads a 50,000-line catalog.
Ask for a number: transactions per month on a platform the vendor runs, and the biggest catalog they have handled.
Check 7. AI features measured by commerce numbers
Product recommendations, customer segmentation, dynamic pricing, visual search, size prediction and inventory forecasting are now standard asks. The test is whether the vendor measures them by conversion rate, return rate and stock efficiency rather than by demo quality. On Woodies Clothing, a fashion brand, EltexSoft built recommendations from purchase and browsing patterns, segmentation for campaigns and demand forecasting as production features that change those numbers. Ask what metric each AI feature moved on a past project, and how it was measured. Our generative AI development page covers the evaluation work behind that.
Check 8. Start speed and team continuity
Two timing questions. First, how fast can engineers start: Nautical Commerce needed a team that could evaluate, onboard and begin building within days, not a proposal with a three-week discovery phase, and the engagement started within a week. Second, who is on the account later: the engineers who learned your catalog model, your tax edge cases and your ERP mapping are the asset, and knowledge walks out with them when a vendor rotates staff between accounts.
Ask for the average tenure of an engineer on a client account, the written replacement commitment, whether the team can scale down to one backend engineer and one QA in a quiet quarter and back up for a peak, and whether you can talk to a client in year three. At EltexSoft the average client engagement is 3.4 years and engineer replacement within two weeks is in the contract; the how we work page has the terms.
Check 9. Pricing, IP and the accounts you own
Senior engineers at nearshore and Eastern European studios run $50 to $99 per hour; US agencies commonly charge $150 to $250 for comparable seniority. What matters is what the rate includes (QA, DevOps, a technical lead, project management) and the minimum term; month-to-month beats a 12-month commitment made before any code exists.
Then the ownership list: code, infrastructure accounts, the Shopify or marketplace admin, payment processor accounts, domains, app store accounts and the data in every third-party system, all in your name from day one, with a documented handover if the engagement ends. A custom commerce build usually lands above the $40K to $100K that a generic MVP costs, because payments, tax, integrations and the release infrastructure are scope, not overhead.
Red flags
- No question about whether an off-the-shelf platform would do.
- "We will use a plugin" as the answer to payments, tax or multi-vendor payouts.
- No CI/CD or staging environment on their current client projects.
- Case studies without transaction volumes, client names or a reachable reference.
- A sales engineer on the discovery call who will not be on the project.
- A 12-month minimum before any code is written.
- Infrastructure, payment or store accounts registered in the vendor's name.
- No written replacement commitment when an engineer leaves.
A 30-minute call script
- Based on what I described, would you build this or put it on a platform, and why?
- Which marketplace or B2B pricing logic have you shipped, and on which platform?
- Draw the money flow: merchant of record, payment splits, refunds, tax, PCI scope.
- Which ERP, CRM or fulfillment systems have you integrated with, and what broke?
- How often does your current client deploy, and can they get a same-day release in peak season?
- What is the largest transaction volume and catalog you run today?
- Who on this call will write code on our project, and how long have they been on their current account?
- What is your rate, what does it include, and what is the minimum term?
- What do we own on day one, and what happens if we stop in month six?
Where EltexSoft fits
We are a Los Angeles software engineering studio founded in 2015, with 35 to 50 senior engineers and no juniors on client projects. Our commerce work includes Nautical Commerce (marketplace platform, $30M Series A, 200,000+ monthly transactions, acquired by Traide), Greek House (Inc. 5000, acquired in 2024) and Woodies Clothing, on Laravel, Django and React; the B2B eCommerce development page lists the scope. Rates are $50 to $99 per hour on a month-to-month retainer, and the first call is with an engineer. If you are shortlisting, we are one of the teams worth 30 minutes. For the general version of this framework, see how to choose a software development partner.