It has been a while I don’t write a post and this is because I was studying for Dev I and II exams. The good news is that I passed both! In this post I am going to try to give some advice about each of the certifications.
1) Always follow the study guides. Here you have the Platform Developer I study guide, and here the Platform Developer II. The areas and percentages indicated there, are thoroughly followed in the tests. I have spent a lot of time studying areas I wasn’t asked about because of not paying all the attention to the study guides.
2) Try to estimate how much effort will these exams cost to you. If you have been working as a Salesforce developer for some time, say 1-2 years, Platform Developer I certification is going to be easily achievable for you, read the study guide, study the topics that sound less familiar to you, and give it a try! However, Platform Developer II is more complicated in my opinion, as it covers integrations, asynchronous processing and a lot of Visualforce. You will need to have more development experience in general to do this one. The bad news is that if you have ever worked as a developer, even Platform Developer I is going to be quite hard for you.
3) Committing to a date can help you to optimize the time that you invest studying. Salesforce is huge, you can’t study everything. According to the estimated effort, decide when do you want to do the test, taking into account the time you will be able to dedicate per week. Once you have selected a date, create a study plan. Divide the remaining time to study cleverly, following the study guide topics, and stick to the plan.
4) Be sure to be checking the up to date material, that applies to the release in which you are going to do the exam. Official online documents are up to date most of the times, but other sources are not.
5) Do the official trailmixes! They are a fun way to learn, but also remember to take notes and review them for the exam, as you may be asked specific details that you need to remember. This one is the Developer I trailmix and this the Developer II one.
6) You can check mock exams that are on the internet to get an idea of which kind of format may the questions have BUT be very careful. Most of the time, these exams contain questions from other certifications (eg: Platform App Builder certification), or the questions are not correct (ambiguous) or the answers are not correct. Bear in mind that Salesforce doesn’t write or review these questions. If you want to be sure an answer is correct, just open an org, and give it a try by yourself!
7) Are you planning to obtain both certifications? Don’t leave too much time between the two exams. The content that you study for Developer I will be covered as well in Developer II. If you leave too much time in the middle, you will need to re-study topics from Developer I.
8) Studying accompanied is much better than studying alone. In my case, I created a study group with my colleagues, and each of us prepared and presented a topic. There are some virtual groups that you can join in the success community too, for example this one.
9) Here I give you some points I was asked about in my Platform Developer I exam:
- Heroku and Heroku Connect – all covered in the trailhead that is recommended in the trailmix!
- Which is automation tool should you use to cover a specific use case. Believe me, you don’t have to know deeply the details of each automation tool. Just the capabilities that each tool has. The comparison table in this page was extremely useful for me.
- How to model a specific use case with relationships in Salesforce, usage of external Ids, and formula fields.
- SOQL queries. Eg: syntax of aggregate queries, return types of each kind of query in Apex, limits that can be reached while executing a SOQL query in Apex…
- Apex basics (data types, properties, static variables, inner classes, how to use describe methods, exceptions, interfaces…) and Apex good practices (bulkification).
- Questions about testing in Apex. You must know about methods and annotations used in test context: seeAllData, @testSetup, Test.startTest()-Test.stopTest(), etc.
- Tools that you can use to deploy metadata, import/export data, run tests, interact with the REST API etc.
- Use cases for Visualforce standard / custom / extension controllers.
- Benefits from lightning component framework architecture and usage of ltg:require.
- Sandboxes types and their differences.
10) And here the same for Platform Developer II:
- Visualforce/Apex/SOQL implications when working with multiple currencies / languages / locales.
- Usage of distance function and geolocation fields.
- Writing REST/SOAP endpoints in Salesforce and how to test them.
- Authentication when invoking REST/SOAP endpoints defined in Salesforce. Certificates. Format of the requests (JSON/XML).
- Invoking REST/SOAP external endpoints from Apex (callouts), and how to test them. Limits that you may reach and good practices.
- Asynchronous processes: @future, batch, queueable, schedulable. Which is the best option for a specific use case. Writing tests for those processes. Limits that you may reach.
- Take a look at all the available Visualforce components and understand what are they for. Also understand very well how standardSetController works.
- Invocable methods.
- Error handling in Apex, Visualforce and Lightning.
- SOQL injection and dynamic SOQL.
- Many questions about trigger order of execution, and which is the expected result for a specific use case. Also Visualforce order of execution.
- How to improve the performance of a Visualforce page, or a piece of Apex code.
This is all, good luck and hope this post helps you to get the certifications!